A sugar-cholestanol compound, in which GlcNAc-Gal-, GlcNAc-Gal-Glc-, Fuc-Gal-, Gal-Glc-, or Gal- is binding to cholestanol having a saturated carbon-carbon double bond in the B ring of cholesterol, exhibits an excellent antitumor activity (see Patent Documents 1, 2, and 3).
Most of such sugar-cholestanol compounds consisting of at least two sugar-chain moieties exhibit antitumor activities. However, these compounds require a complicated process for synthesis and a higher production cost as the number of sugar-chain moieties increases. Meanwhile, a sugar-cholestanol compound having galactose as a single sugar moiety has been reported so far, but its activity has still been unsatisfactory. Furthermore, those sugar-cholestanol compounds share the same problem in that they are generally water-insoluble.
Thus there has been a growing demand for a new sugar-cholestanol compound which has a small number of short sugar chain moieties, exhibits enough anticancer activity, and is excellent in solubility.
A cholestanol compound having N-acetyl-D-glucosamine (GlcNAc) as a sugar-chain moiety is a known compound (see Non-Patent Document 1), but no report has yet been made to its bioactivity.
[Patent Document 1] JP-A-11-60592
[Patent Document 2] JP-A-2000-191685
[Patent Document 3] WO 2005/007172 pamphlet
[Non-Patent Document 1] Studies on steroids. Part CXXXXV. Synthesis of conjugated cholesterol and cholestanols. (1979), 27 (8), 1926-31.